#!/usr/bin/env python2.7
#-*-coding:utf-8-*-

class Animal(object):
	pass

class Dog(Animal):
	
	def __init__(self,name):
		self.name=name

class Cat(Animal):
	def __init__(self,name):
		self.name=name

class Person(object):
	def __init__(self,name):
		self.name=name
		self.pet=None

class Employee(Person):
	def __init__(self,name,salary):
		self.name=name
		self.salary=salary

class Fish(object):
	pass

class Salmon(Fish):
	pass

class Halibut(Fish):
	pass

rover=Dog('Rover')
satan=Cat('Satan')
mary=Person('Mary')
mary.pet=satan
frank=Employee('Frank',200000)
frank.pet=rover
flipper=Fish()
crouse=Salmon()
harry=Halibut()
